V700 scanner head assembly - intermittent trouble

So my Epson V700 won't do transparencies. The assembly in the bed is kaput. The light bar in the bed stopped lighting and I took it to the repair shop where it worked just fine. Brought it home and continued scanning and now the light bar is out again. Same result with both silverfast and epson software. Repair of labor and new scanner head assembly is $400 and a new scanner about $519 - hardly worth repairing. I don't have the funds for repairs right now and am wondering if anyone has any ideas of possibly attempting a repair of my own. I suppose I could disassemble and see if I can find a loose connection. A loose connection might account for why it works / doesn't work / works / doesn't work.

Any thoughts?

If you have checked the exteranl pigtail connection, it does sound like it is time to open it up and check for a loose connector or soldering joint that needs to be remelted. As you say, the repair price is too high to be practical. Here are some diagrams:

How To Dismantle Epson Scanners

Doug

Doug is right about first checking the connection between the top and the base (the "pigtail connection"). If that is loose, you'll see the behavior you describe. Check that carefully before you open up the machine.

Actually, its the light in the lid that's out- not the bed.

The pigtail connects the bed (where the power supply is) to the lid. So if the light/motor/whatever in the lid is not working, first thing to check is the external wire that connects the lid to the bed, which sticks out the back of the lid and plugs into the bed. Check it.

Checked

Yes, I've unplugged it and replugged securely. Twisted and jiggled. To no effect.